The present invention relates to an object detector employing a superconductive device, and more particularly, to an object detector for an air conditioner which detects the information of the number, locations, and movement of persons in a plurality of detection areas, and outputs a control signal based on the information.
An infrared object detector employing a superconductive device finds its general use in a burglar alarm device or in a device for automatically opening and shutting a door. Recently, studies have been actively conducted on applications of the infrared object detector to an air conditioner or a camera, to more accurately detect the distance to an object such as a person, its location and movement.
FIG. 1 illustrates an example of a conventional infrared detector applied to an air conditioner. This infrared detector detects the information of a person present indoor, and controls the output of the air conditioner for an adequate cooling according to the information.
Referring to FIG. 1, the conventional object detector for an air conditioner has a cover member 12 covering a printed circuit board (PCB) 11 to form a predetermined space therebetween. A pair of superconductive devices 13 and 13' of a thin film type are spaced in parallel by a predetermined distance inside the space. Light incident apertures 14 and 14' are formed at the cover member 12 to correspond to the superconductive detecting devices 13 and 13', respectively. A blocking plate 15 is provided inside the cover member 12, facing between the superconductive devices 13 and 13'. In addition, the superconductive devices 13 and 13' are sequentially connected to their respective amplifiers 16 and 16', window comparators 17 and 17', and timers 18 and 18', thereby constituting a circuit for processing a signal.
In the conventional object detector for an air conditioner as constituted above, when a person indoor moves from a view A to a view B, as shown in FIG. 1, polarization takes place with a time interval between the superconductive detecting devices 13 and 13', and signals are output from impedance transform devices (not shown). The output signals are amplified in the amplifiers 16 and 16', and the amplified signals are converted into square wave signals by high and low level reference voltages in the window comparators 17 and 17' Timers 18 and 18', which are provided for precluding impacts of ambient changes, ignores the later one of the output signals for a predetermined time by the earlier one of the output signals, to thereby prevent a malfunction.
This conventional object detector for an air conditioner exhibits its limitations in achieving the comprehensive information of persons present indoor, including number, location and movement distance, since its detective operations are confined to their movement directions. Therefore, it is impossible to control an air conditioner to operate in an optimum state.